Electronic annotation of documents with preexisting content

1. A method for annotating a printed document having preexisting content, the method comprising:

identifying a first copy of the printed document having preexisting content, wherein the first copy of the printed document is printed from a digital document having a corresponding digital version of the preexisting content;

storing first handwritten annotations captured from a first smart pen interacting with the first copy of the printed document having the preexisting content;

identifying a second copy of the printed document having the preexisting content, wherein the second copy of the printed document is printed from the digital document having the corresponding digital version of the preexisting content;

storing second handwritten annotations captured from a second smart pen interacting with the second copy of the printed document having the preexisting content;

merging the first handwritten annotations and the second handwritten annotations to generate a collective set of handwritten annotations;

associating the collective set of handwritten annotations with the digital version of the preexisting content;

storing the first and second captured handwritten annotations in association with the digital version of the preexisting content as an annotated digital document;

detecting a background color of a particular area of the annotated digital document, the particular area having at least a portion of the first captured handwritten annotations; and

formatting the portion of the first captured handwritten annotations in the particular area of the annotated digital document to have a color selected based on the detected background color.

2. The method of claim 1 , wherein the first copy of the printed document comprises an encoded dot pattern recognizable by the first smart pen, and wherein associating the first captured handwritten annotations with the digital version of the preexisting content comprises using the encoded dot pattern to determine coordinate information for the first captured handwritten annotations.

3. The method of claim 1 , wherein storing the first captured handwritten annotations in association with the digital version of the preexisting content comprises overlaying an electronic representation of the first captured annotations together with the digital version of the preexisting content in the annotated digital document.

4. The method of claim 1 , further comprising performing character recognition on the first captured handwritten annotations and storing recognized characters in the annotated digital document.

5. The method of claim 1 , further comprising performing character recognition on the digital document to recognize characters in the preexisting content and storing recognized characters in the annotated digital document.

6. The method of claim 1 , further comprising capturing audio concurrently with capturing the first handwritten annotations, and storing the captured audio in association the first captured handwritten annotations.

7. The method of claim 1 , further comprising:

capturing a user interaction with a portion of the preexisting content printed on the printed document using the smart pen;

capturing audio using the smart pen concurrently with capturing the user interaction; and

storing the captured audio in association with the portion of the digital version of the preexisting content based on the user interaction with the preexisting content in the printed document.

8. The method of claim 1 , wherein storing the first captured handwritten annotations in association with the digital version of the preexisting content comprises:

storing a first layer of the annotated digital document comprising the first captured handwritten annotations; and

storing a second layer of the annotated digital document comprising the preexisting content.

9. The method of claim 1 , further comprising:

recognizing a formatting gesture associated with a portion of the preexisting content; and

formatting the portion of the preexisting content in the digital document according to the formatting gesture.

10. A computer program product for annotating a printed document having preexisting content, the computer program product comprising a non-transitory computer-readable storage medium containing computer program code for:

identifying a first copy of the printed document having the preexisting content, wherein the first copy of the printed document is printed from a digital document having a corresponding digital version of the preexisting content;

receiving from a first smart pen, first handwritten annotations on the printed document, the first handwritten annotation captured using the first smart pen;

identifying a second copy of the printed document having the preexisting content, wherein the second copy of the printed document is printed from the digital document having the corresponding digital version of the preexisting content;

receiving from a second smart pen, second handwritten annotations on the second copy of the printed document, the second handwritten annotation captured using the second smart pen;

merging the first handwritten annotations and the second handwritten annotations to generate a collective set of handwritten annotations;

associating the collective set of handwritten annotations with the digital version of the preexisting content;

storing the first and second captured handwritten annotations in association with the digital version of the preexisting content as an annotated digital document;

detecting a background color of a particular area of the annotated digital document, the particular area having at least a portion of the first captured handwritten annotations; and

formatting the portion of the first captured handwritten annotations in the particular area of the annotated digital document to have a color selected based on the detected background color.

11. The computer program product of claim 10 , wherein the first copy of the printed document comprises an encoded dot pattern recognizable by the first smart pen, and wherein associating the first captured handwritten annotations with the digital version of the preexisting content comprises using the encoded dot pattern to determine coordinate information for the first captured handwritten annotations.

12. The computer program product of claim 10 , wherein storing the first captured handwritten annotations in association with the digital version of the preexisting content comprises overlaying an electronic representation of the first captured annotations together with the digital version of the preexisting content in the annotated digital document.

13. The computer program product of claim 10 , wherein the non-transitory computer-readable storage medium further contains computer program code for:

performing character recognition on the captured handwritten annotations and storing recognized characters in the annotated digital document.

14. The computer program product of claim 10 , wherein the non-transitory computer-readable storage medium further contains computer program code for:

performing character recognition on the digital document to recognize characters in the preexisting content and storing recognized characters in the annotated digital document.

15. The computer program product of claim 10 , wherein the non-transitory computer-readable storage medium further contains computer program code for:

capturing audio concurrently with capturing the first handwritten annotations, and storing the captured audio in association the first captured handwritten annotations.

16. The computer program product of claim 10 , wherein the non-transitory computer-readable storage medium further contains computer program code for:

capturing a user interaction with a portion of the preexisting content printed on the printed document using the smart pen;

capturing audio using the smart pen concurrently with capturing the user interaction; and

storing the captured audio in association with the portion of the digital version of the preexisting content based on the user interaction with the preexisting content in the printed document.

17. The computer program product of claim 10 , wherein storing the first captured handwritten annotations in association with the digital version of the preexisting content comprises:

storing a first layer of the annotated digital document comprising the first captured handwritten annotations; and

storing a second layer of the annotated digital document comprising the preexisting content.

18. The computer program product of claim 10 , wherein the non-transitory computer-readable storage medium further contains computer program code for:

recognizing a formatting gesture associated with a portion of the preexisting content; and

formatting the portion of the preexisting content in the digital document according to the formatting gesture.

19. A smart pen computing system for annotating a printed document having preexisting content, the smart pen computing system comprising:

a first smart pen configured to identify a first copy of the printed document having preexisting content and for capturing first handwritten annotations on the first copy of the printed document, wherein the first copy of the printed document is printed from a digital document having a corresponding digital version of the preexisting content;

a second smart pen configured to identify a second copy of the printed document having preexisting content and for capturing second handwritten annotations on the second copy of the printed document, wherein the second copy of the printed document is printed from the digital document having the corresponding digital version of the preexisting content; and

a non-transitory computer-readable storage medium storing computer-executable program instructions for:

receiving the first handwritten annotations from the first smart pen;

detecting a background color of a portion of the printed document having the first captured handwritten annotations;

receiving the second handwritten annotations from the second smart pen;

merging the first handwritten annotations and the second handwritten annotations to generate a collective set of handwritten annotations;

associating the collective set of handwritten annotations with the digital version of the preexisting content;

storing the first and second captured handwritten annotations in association with the digital version of the preexisting content as an annotated digital document;

detecting a background color of a particular area of the annotated digital document, the particular area having at least a portion of the first captured handwritten annotations; and

formatting the portion of the first captured handwritten annotations in the particular area of the annotated digital document to have a color selected based on the detected background color.

20. The system of claim 19 , wherein the first smart pen comprises:

a gesture capture system adapted to capture the first handwritten annotations;

a memory adapted to store the first captured handwritten annotations; and

an interface adapted to transfer the first handwritten annotations from the memory to an external computing system that stores the captured handwritten annotations in association with the digital version of the preexisting content.

21. The smart pen computing system of claim 19 , wherein the first smart pen further comprises:

a processor for processing the handwritten annotations captured by the imaging system and for determining an identifier of the printed document based on information captured by the gesture capture system.

22. The smart pen computer system of claim 19 , wherein the first smart pen further comprises:

a microphone for capturing audio capturing audio concurrently with capturing the first handwritten annotations.

23. The smart pen computing system of claim 20 , wherein the first smart pen further comprises:

a character recognition system for recognizing characters in the first handwritten annotations, and wherein the interface is adapted to transfer the recognized characters to the external computing system.

24. A method for annotating a printed document having preexisting content, the method comprising:

identifying the printed document having the preexisting content, wherein the printed document is printed from a digital document having a corresponding digital version of the preexisting content;

storing handwritten annotations captured from a smart pen interacting with the printed document having the preexisting content;

detecting a background color of a portion of the printed document having the captured handwritten annotations;

associating the captured handwritten annotations with the digital version of the preexisting content;

storing the captured handwritten annotations in association with the digital version of the preexisting content as an annotated digital document;

detecting a background color of a particular area of the annotated digital document, the particular area having at least a portion of the first captured handwritten annotations; and

formatting the portion of the captured handwritten annotations in the particular area of the annotated digital document to have a color selected based on the detected background color.